There have been many attempts to develop cell culture systems for metabolic studies of chemicals, particularly for the short term assay of potential carcinogens and mutagens. The cell cultures in general use for such purposes are derived from rodents and, although they actively metabolize chemicals generally thought to be carcinogenic, the metabolites are different from those produced in normal human primary cultures. Human fibroblastic cell strains have been tested for their ability to convert potential carcinogens and mutagens to active carcinogens, but their ability to effect such metabolic conversions is low.
There are a number of problems associated with the growth of viruses for the production of vaccines. In particular, fastidious viruses, such as hepatitis B virus (HBV), have not been propagated successfully in cell cultures. Thus, cell culture systems capable of rapid growth which support production of viral components must be found in order for a vaccine to be produced from such fastidious viruses.